Commonly used toothbrushes employ various schemes in which bristles made of a synthetic resin material are planted on a flat head at regular intervals and the bristles are made to have different lengths or diameters so that the bristles can come into close contact with the curved surfaces of teeth and thus maximize a tooth brushing effect.
Furthermore, in the conventional toothbrushes, the bristles are planted upright on the flat head, and thus the bristles cannot be deformed in accordance with the shapes of teeth during tooth brushing, with the result that a contact area is small and thus frictional force is reduced. Therefore, the frictional force of the bristles is not uniformly applied to the surfaces of teeth during tooth brushing, and thus a tooth brushing effect has to be reduced.
In order to overcome the problems of the conventional toothbrushes, the inventor of the present invention has been issued patents and a utility model registration as Korean Patent No. 10-0814127, Korean Patent No. 10-1184334, Korean Patent No. 10-1184337, Korean Patent No. 10-1321571, Korean Patent No. 10-1388967, and Korean Utility Model Registration No. 20-0462621 for a plurality of toothbrushes.
However, the toothbrushes of the patents and the utility model registration require larger numbers of parts and manual processes, and thus problems arise in that productivity is reduced and a unit production cost is increased. Accordingly, there is an urgent need for a means for overcoming these problems.